Speed measurement system with onsite digital image capture and processing for use in stop sign enforcement

ABSTRACT

A speed measurement system for measuring speeds of vehicles, capturing images of vehicles, and detecting violation of stop sign and traffic signal laws. The system includes a laser speed detector for determining a speed of a vehicle adjacent a stop sign. When a speed is determined, the detector generates a speed signal. The system includes a camera generally aligned with the speed detector operable to capture and store digital still images of vehicles in memory. The camera is programmed to respond to an image capture signal to generate and transmit a digital image file including a still image of the vehicle targeted by the detector. A portable processor is linked to the speed detector and the camera to first receive the speed signal, to compare the detected speed with a threshold speed, to transmit an image capture signal to the camera, and to receive the image file from the camera.

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This is a continuation-in-part of application Ser. No.09/812,228, filed Mar. 19, 2001, which claims the benefit of U.S.Provisional Application No. 60/191,171, filed Mar. 22, 2000.

BACKGROUND OF THE INVENTION

[0002] 1. Field of the Invention

[0003] The present invention relates, in general, to speed detection ofmoving vehicles, and more particularly to compact, mobile speeddetection systems that provide for accurate speed detection withaccompanying image capture, processing, and production at the locationof the field portion of the system, such as the present location of thelaw enforcement vehicle.

[0004] 2. Relevant Background

[0005] Law enforcement agencies and personnel presently use a variety ofspeed measurement devices to monitor traffic and, more particularly, toidentify vehicles that are going faster than posted speed limits. Inaddition to identifying a speeding vehicle, it has become increasinglycommon to attempt to capture images of such speeding vehicles and thento use the images to better enforce the speed limits (i.e., use theimage as part of a ticketing program). While satisfying some of theneeds of the law enforcement agencies, the existing speed measurementand image capture devices have not proven suitable or reliable for manylaw enforcement agency applications and have created operationalproblems that hinder the field use of such devices.

[0006] Various methods are used to detect the speed of moving vehicles,such as well-known radar systems. More recently, speed detection systemshave incorporated lasers to accurately detect the speed of a movingvehicle and also the distance or range of the vehicle from the laserdevice. In general, laser speed detectors measure the time delay betweenthe transmission of a series of pulses and a reflection of those pulses.The design and operation of laser speed detection and range findersystems may be found in U.S. Pat. No. 5,359,404 entitled “Laser-BasedSpeed Measuring Device, U.S. Pat. No. 5,652,651 entitled “Laser RangeFinder Having Selectable Target Acquisition Characteristics and RangeMeasuring Precision”, and U.S. Pat. No. 6,057,910 entitled“Self-Calibrating Precision Timing Circuit and Method for Laser RangeFinder”, which are each incorporated herein by reference. Typically,these laser speed detection systems provide accurate measures of avehicle's speed and are useful for providing onsite speed measurements,e.g., at the location of a law enforcement vehicle, that could then beentered on a ticket by law enforcement personnel.

[0007] Improvements have been made to increase the accuracy andusefulness of these laser-based speed detection systems. For example,U.S. Pat. No. 5,938,717 entitled “Speed Detection and Image CaptureSystem for Moving Vehicles”, which is incorporated herein by reference,discloses a system for accurately aligning a laser speed detector andfor capturing an image of a speeding vehicle with a video camera. Thesystem also provides the advantage of automating the capture of imagesof speeding vehicles at a predetermined distance from the system and ofcapturing a set of useful information (e.g., date, time, location, speedlimit, detected speed, and the like). A computer system is included inthe disclosed system to run a frame grabber program to capture a frameof the video image. The computer system includes a removable datastorage device for storing the captured image frames and the associatedset of information.

[0008] Generally, the system is taught to be operated by placing thesystem in a selected location to monitor vehicle speeds, such as along aroad with the bulky computer system position in the back of a van orother vehicle. The system is initially set up by an operator and thenallowed to operate automatically without or with minimal operatorcontrol for a certain period of time. An operator then removes the datastorage device from the system and takes the data storage device back toa separate office or facility for processing of the captured images(i.e., grabbing a still image from the video) and data with a computersystem at the office. In this manner, tickets can be produced bycombining the video image with the collected data and then mailing theticket to owners of vehicles that violated a speed limit by a selectedamount (such as 5 miles per hour in a school zone and 10 miles per hourfor a highway). A hardcopy of the image may be included with the ticketwith the data being overlaid by the office computer system. In someapplications, the field computer system, such as a personal computer,includes a monitor to allow an operator to view the collected image andto facilitate entering of field parameters. Additionally, the fieldcomputer system may perform some of the processing features (such asoverlaying of the set of information on a grabbed frame of the video)and may include a thermal printer to produce copies of the image withthe overlaid information at the field unit.

[0009] While addressing some of the needs of law enforcement agencies,the video-based laser speed detection systems have not addressed all ofthe operating problems facing field operators and are not particularlyuseful in some field applications. For example, the use of framegrabbing with a video camera for image capturing is most effectivewith-a relatively high capacity and higher speed data processing systemand large data storage capacity. Typically, the computer requirementsare met with a personal computer with central processing unit with aframe grabber PC card installed and associated monitor and keyboard. Thecombined use of a video camera with a personal computer results in abulky package that is often costly and is usually physically large,which limits its usefulness in the field. It is not convenient or evenpractical for a single operator, i.e., law enforcement officer, toquickly deploy the system and then periodically move the entire systemor portions of the system without moving the whole vehicle in which thesystem is positioned. The portability of these video-based systems isfurther limited by the need for a large number of communication cablesand power cords (e.g., generally AC and DC power provided to eachcomponent) between the various components.

[0010] One of the most significant advantages of a laser-based speedmeasurement instrument is its ability to narrowly target a single carwithin a group of cars. However, there is still a need for proof thatthe detected speed is matched with the correct car. This proof can beprovided with the overlaid information if it is accurately synchronizedwith the proper, grabbed video frame. Of course, this synchronizationand combining of information requires additional processing capacitythat increases the cost and sometimes the size of the system. Also, thetime required to process the information and to print out a hard copy ofthe produced image limits its desirability as evidence or proof ofspeeding in the field as enforcement officers demand relatively quickevidential support to be used during the issuance of a speeding ticket.

[0011] Hence, there remains a need for a device or system for detectinga speed of a moving vehicle and for capturing an image of the vehiclethat provides an accurate determination of the vehicle's speed alongwith readily accessible proof that the speed has been correctly matchedto the proper vehicle. Preferably, such a speed measurement device wouldbe designed for field use (such as inside or outside an operator'svehicle) providing prompt and useful evidence of a vehicle's speed whilealso being compact, lightweight, and easy to operate. The device wouldalso preferably be useful in various weather conditions, provideprotection of collected images and data, and be relatively inexpensiveto purchase and operate.

SUMMARY OF THE INVENTION

[0012] The present invention addresses the above discussed andadditional problems by providing a compact and portable speedmeasurement and image capture system that combines an accurate laserspeed detector with a programmable digital camera and a portable fieldprocessor. The portable field processor is configured to allow anoperator to enter capture session and system parameters, such as aposted speed limit and a capture speed level, and to receive vehiclespeed signals from the speed detector. The portable field processoroperates to selectively transmit image capture signals to the digitalcamera in response to these speed signals (e.g., generates image capturesignals when the capture speed level is exceeded). The digital camera isprogrammed to retrieve a still image of the vehicle from its buffers ormemory and create and transmit a digital image file (such as a filecompressed per JPEG standards). The portable field processor then writesthe speed signal data into the digital image file and displays thecombined file on a display screen. The portable field processor can thenbe detached from the system by a field operator to show the displayedimage to a vehicle operator. In one embodiment, a classification sensoris provided to detect whether the vehicle is a commercial vehicle, suchas by height measurements, axle counting, weight measurements, and thelike, and two distinct capture speed levels are used to effectivelycapture images of private and commercial speeding vehicles that may havedifferent speed limits.

[0013] According to one aspect of the invention, a compact speedmeasurement system is provided for field or onsite use in measuringspeeds of vehicles and capturing images of select vehicles. The systemincludes a laser-based speed detector for determining a speed of avehicle in a specific target area. When a speed is determined, thedetector generates a speed signal. The system also includes a cameragenerally aligned with the speed detector operable to capture and storedigital-format still images of vehicles in memory. Specifically, thecamera is programmed to respond to an image capture signal to generateand transmit a digital image file including a still image of the vehicletargeted by the detector. A portable field processor is communicativelylinked to the speed detector and the camera to first receive the speedsignal, to process the speed signal and in response transmit an imagecapture signal to the camera, and to receive the digital image file fromthe camera.

[0014] In a preferred embodiment, the portable field processor includessoftware to create a combined speed and image data file by modifying thedigital image file to include speed data from the speed signal. Forexample, the digital image file may be a JPEG-format file and themodifying may involve writing the speed data to the header of the JPEGfile. The portable field processor includes a display screen and isconfigured to display the modified digital image file on the displayscreen. An operator can then operate the field processor to enlargeand/or enhance selected portions of the displayed image (such as toenlarge the license plate portion of the image). The field processor canbe readily detached from the system and hand carried to a stoppedvehicle to show the vehicle operator the displayed image as proof oftheir speed. To control the risk of data loss, the system is configuredsuch that the digital camera acts as a charging power source for thefield processor, i.e., the camera will stop operating before the fieldprocessor loses power thus assuring storage of all captured images.

[0015] According to another aspect of the invention, a method isprovided for measuring a speed of a moving vehicle and capturing adigital image of the same moving vehicle. The method involves initiallypositioning and setting up a speed detector and a camera at a locationselected by an operator for targeting vehicles moving through a targetarea. The camera is operated on an ongoing basis to capture ortemporarily store a still image of each vehicle passing through thetarget area. The speed detector operates on an ongoing basis todetermine the speed of a specific vehicle in the target area. The speeddata including the determined speed is transmitted to a portable fieldprocessor. The speed data is processed by the field processor, whichresponds by transmitting a trigger signal to the camera. The camerareceives the trigger signal, responds by retrieving a still imagecorresponding to the targeted vehicle, and then transmits the stillimage in a digital image file to the portable field processor.

[0016] In one embodiment of the method, several of the functions aresynchronized to insure that the captured image is an image of the samemoving vehicle that was targeted by the speed detector. This is achievedby determining the speed at a speed measurement time with the detectorand operating the camera to store still images during an image timingcycle. Synchronization occurs by operating the field processor totransmit the trigger signal within the timing cycle that also coincideswith the speed measurement time.

[0017] In another embodiment of the method, the method includesdetermining the classification of the vehicle, such as with a separateclassification sensor (e.g., a height sensor). The classifications mayinclude private or lower weight vehicles, commercial trucks or higherweight vehicles, and other classifications that may be used bygovernments in establishing differing speed limits (e.g., 55 mph forcommercial vehicles and 65 mph for private vehicles). In thisembodiment, the processing of the speed data includes first identifyingthe classification of the vehicle (such as from the combined speed datastring including vehicle speed, range of vehicle from speed detector,and the vehicle type) and then comparing the detected speed with thespeed limit for that type of vehicle. Vehicle classification in themethod may be achieved in many ways. For example, vehicle classificationmay include sending a signal directly to the field processor from aseparate sensor configured to detect vehicle type or classification mayinclude concatenating vehicle type information onto the laser speeddetector data string.

[0018] In another embodiment of the invention, a stop sign enforcementsystem is provided in which the portable field processor is configuredfor traffic sign or signal enforcement, e.g., compliance with stopsigns. The portable field processor may include a stop sign or trafficsignal software module or otherwise be configured, such as by properentry of operating parameters for its base operating software, todetermine when whether a vehicle complies with a traffic sign or signal.In this embodiment, the system includes a laser speed detector and adigital camera that are positioned with a line of sight to a trafficsign or signal, such as a stop sign, and a lane of a road adjacent thesign (i.e., where vehicles are supposed to stop for the sign).

[0019] The system may be positioned in front of or behind a traffic signor signal so as to enforce the sign or signal with a front or rear viewof vehicles relative to the signal or sign. The laser speed detector isranged or used to measure the distance to the sign by aiming it at theback or front of the stop sign or traffic signal. Once the measurementdistance is identified, the laser detector (with the aligned andcombined camera) is aimed at a center portion of the road lane whereenforcement is desired. The portable field processor includes a displayfor allowing an operator to configure the system for traffic signalenforcement, such as by selecting a stop sign enforcement operating mode(or an automatic capture mode), and to input an enforcement ormeasurement window (i.e., an area relative to the traffic signal orsign) and/or a capture speed threshold.

[0020] The threshold is typically set in the range of 10 to 20 mph (atwhich point it is unlikely that a vehicle would be able to stop at thesign) or set as percentage of the posted speed limit (such as 50 to 100percent of the limit of the road lane, e.g., 30 mph in a 45 mph speedzone). The system is then allowed to operate for a period of timeautomatically capturing and storing vehicles that violate or “run” thestop sign or other traffic signal (such as a railroad crossing ortraffic light). System operation includes the detector detecting a speedof a vehicle that enters the detector's enforcement window (e.g.,detection typically begins a preset distance beyond (or in front of ifdetecting from behind the vehicle) the measurement distance, such as,but not limited to, 10 to 20 feet) and transmits a speed data signal tothe portable field processor. The processor uses the stop signenforcement module or internal programs with appropriately setparameters and configuration to compare the detected speed indicated inthe signal to the threshold. When the threshold is exceeded, theprocessor transmits a trigger signal to the camera. The camera thenretrieves a digital-format still image (of the same vehicle for whichthe speed was detected) and transmits this to the processor as a digitalimage file for combining with the speed data (such as in the image fileheader) and then later downloading for use in creating a trafficviolation citation or ticket. In some embodiments, the image file andspeed data are maintained as separate files that are linked or matchedor that are later combined.

BRIEF DESCRIPTION OF THE DRAWINGS

[0021]FIG. 1 is a schematic block diagram illustrating an implementationof a speed measurement and image capture system according to the presentinvention.

[0022]FIG. 2 is an illustration of a display screen of the portablefield processor of FIG. 1 as it would be viewed by an operator of theprocessor and by a vehicle driver.

[0023]FIG. 3 is front perspective view of an embodiment of the speedmeasurement and image capture system of FIG. 1 illustrating thecompactness of the system as the entire system is mounted on a standardphotographers tripod.

[0024]FIG. 4 is a rear perspective view of the system of FIG. 1 similarto FIG. 3 illustrating the operator's view of the system and showing thefield processor housing for holding and viewing the portable fieldprocessor.

[0025]FIG. 5 is rear side view of the system of FIGS. 3 and 4illustrating the detachable mounting bracket and the communication andpower ports or connections of the system components.

[0026]FIG. 6 is a flow diagram illustrating the acts and features ofoperating the speed measurement and image capture system to capture andprocess images and then display the images to a vehicle operator with aportable field processor.

[0027]FIG. 7 is a schematic block diagram illustrating anotherimplementation of a speed measurement and image capture system accordingto the present invention that is configured more specifically for stopsign (or signal enforcement).

[0028]FIG. 8 is a flow diagram illustrating the acts and features ofoperating the speed measurement and image capture system of FIG. 7 tocapture and process images of vehicles determined by the system to beviolating a stop sign or other sign or signal requiring a vehicle tostop at specific location.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0029]FIG. 1 illustrates one embodiment of a speed measurement and imagecapture system 100 that is especially configured to be used in the fieldby law enforcement officers. In this regard, the system 100 includescomponents that can be combined into a compact and portable unit forready mounting on a tripod or onto a bracket of a vehicle.Significantly, the system 100 also includes a portable field processor110 that is designed to receive digital information (i.e., captureddigital images and detected speeds and ranges), to process theinformation (such as by zooming in on a vehicle operator's face and/or alicense plate on the vehicle), and to be detached from the system 100 tobe carried over to the vehicle. The captured and processed image canthen be easily displayed to the vehicle operator on a display screen 112of the portable field processor 110. These and other features, such asthe use of a digital camera battery to trickle feed power to theportable field processor 110 to enhance data storage and security, willbe discussed in detail below. An overview of the system 100 will firstbe provided followed by an in depth discussion of the individualcomponents of the system 100 and their operation.

[0030] As illustrated, the speed measurement and image capture system100 includes a portable field processor 110 in communication with both alaser speed detector 130 and a digital camera 140. As will become clear,the laser speed detector 130 is utilized by the portable field processor110 to obtain a speed of a moving vehicle 134 and the vehicle's range ordistance from the detector 130. Concurrently, the digital camera 140 isoperated by the portable field processor 110 to capture an image of thefront portion of the vehicle 134. During operation, the digital image iscombined with the detected speed and range information by the portablefield processor 110 for use in proving that a vehicle was going thedetected speed (e.g., violating a posted speed limit).

[0031] The laser speed detector 130 may be any of a number oflaser-based speed and range detection devices that are useful fordetermining speed and range of a vehicle or other object from thedetector 130 at the time the determination was made. Additionally, thedetector 130 preferably is configured to provide the determined speedand range information over a communication link to the input/output port122 of the portable field processor 110 (e.g., in digital form). In onepreferred embodiment, the laser speed detector 130 is a laser-basedsensor device such as that available from Laser Technology, Inc.,Englewood, Colo. under the product name of UltraLyte, which operateseffectively to determine the speed and range measurement data and todownload the data to the portable field processor 110 (e.g., at a baudrate of 9600 or higher). As shown, the portable field processor 110includes memory 120 for storing the speed and range measurement datafrom the laser speed detector 130.

[0032] The digital camera 140 is a significant feature of the system 100providing the key functions of capturing and delivering a digital imagewhen prompted by the portable field processor 110 and of acting as thecharging power supply for the portable field processor 110. The digitalcamera 140 is preferably fully programmable and is selected to create adigital still image on demand and to download the image (e.g., acompressed digital file such as JPEG file) to the portable fieldprocessor 110, which can append the speed and range information to thedigital image file such as in the JPEG file header.

[0033] The digital camera 140 is included to provide the proof that thecorrect vehicle 134 has been targeted by the laser speed detector 130 bytaking or capturing a digital image of the vehicle 134 as the speed issubstantially concurrently (i.e., within an acceptable time window, asdiscussed below) being determined by the detector 130. In other words,the operation of the digital camera 140 and laser speed detector 130 aresynchronized by the portable field processor 110. The digital camera 140includes a lens 142 which is selected such that the camera 140 cancapture vehicle images which can be resolved to accurately show thevehicle license plate (and in some embodiments, the vehicle operator'sface). The digital camera 140 has a range or field of resolution thatpreferably coincides with, or is larger than, the target area of thelaser speed detector 130 (e.g., a range of 0 to 125 meters or more). Thedigital camera 140 is powered by an integral battery 144, which is alsoused to provide power to the portable field processor 110 via powersupply port 124 as is discussed in detail below.

[0034] As with the laser speed detector 130, the digital camera 140 maytake many forms and configurations to provide the features andoperational advantages of the present invention. In one embodiment, thedigital camera is a high-speed Ethernet camera (such as those availablefrom JVC under Model No. VN-C1U) that is interfaced with the portablefield processor 110 with a network card (such as a Compact Flash networkcard) in the input/output 122 of the processor 110. This type of digitalcamera is desirable for the camera 140 because it has a high datatransfer speed and is programmable but many other digital cameras may beemployed in the invention. In one preferred embodiment, the camera 140is operated in a mode to automatically compress captured images into aJPEG format which reduces the file size of the images prior to thembeing transferred to the portable field processor 110. The initial setup(e.g., parameter setup) and image capture request communication from theportable field processor 110 to the camera 140 is typically performedvia an Ethernet connection (e.g., a 10Base-T Ethernet LAN) with UDP orother protocol to provide a connection rate useful for rapidlydownloading the digital images from the camera 140 to the processor 110.

[0035] The camera 140 preferably is able to operate in an automatic modeand in a manual mode. In the automatic mode, the camera 140automatically adjusts the exposure, gain, brightness, and otheroperating parameters to provide a high quality image. In manual mode,the camera 140 can be adjusted by an operator or by the processor 110 toset a number of operating parameters. For example, the followingparameters may be set (with one preferred setting provided inparentheses): image resolution (640×480 pixels); JPEG compression (lowor best resolution for camera 140); exposure ({fraction (1/1000)}second); gain (minimum=150, average setting=200, and maximum=255) ;frame rate (maximum for camera 140 such as 30 frames/second); contrast(default of camera 140); brightness (median setting for camera 140); andsharpness (default of camera 140). Other operating parameters andsettings will be apparent to those skilled in the art to obtain a clearenough image to identify a license plate and/or vehicle operator.

[0036] In this regard, a number of lens systems 142 may be utilized toobtain a desirable captured image, such as a lens system with a225-millimeter focal length. In a preferred embodiment, the lens system142 provides a full field-of-view of 1.5 degrees and is focused at 80meters to obtain sharp images from 50 to 120 meters. Of course, thefocus distance is preferably matched to the target field capacity andsetting of the laser speed detector 130. In practice, the only camera140 adjustment that is manually performed in the field is adjustment ofthe aperture. Other operating parameters, such as gain, are set by anoperator of the system 100 via the portable field processor 110 byentering information in a capture setup screen (discussed in more detailbelow).

[0037] According to one important feature of the invention, the system100 is configured such that the digital camera 140 functions as acharging power source for the portable field processor 110. Thisarrangement enables the processor 110 to be fully charged even when thedigital camera 140 does not have enough power to continue to operate(i.e., when its battery 144 is depleted) which provides an added levelof data protection for previously captured images and speed and rangeinformation with data loss being unlikely. This charging feature may becarried out in a number of ways, and the following embodiment isexemplary only and not limiting of the breadth of the invention.

[0038] In one embodiment, the camera 144 includes a battery 144 thatprovides the needed input power for operating the camera 140. Forexample, the battery 144 may be a readily available 7.2 VDC rechargeablelithium ion battery or other type and rating battery that can be mountedto the camera 140. In some embodiments, the camera 140 operates at adifferent power level than provided by the battery 144 (or desired byprocessor 110) and a step-down regulation board (not shown) is mountedbetween the camera 140 and the battery 144 (e.g., the camera 140 mayrequire 5 VDC input power and the step-down regulation board would beconfigured to step down the 7.2 VDC to 5 VDC). Further, a switch (notshown) may be provided to break the connection between the battery 144and the regulation board.

[0039] To provide a trickle charge to the processor 110, thestepped-down voltage may be provided to the processor battery system126. As illustrated, the battery 144 is connected directly to the powersupply port 124 that feeds the charging power to the battery system 126of the processor 110. A step-down regulator (not shown) may be providedin the processor 110. Alternatively, the stepped-down power from theregulation board (not shown) in the camera 140 can be fed through thecommunication line to the input/output port 122 of the processor 110.For example, the processor 110 power supply wiring may be included inthe Ethernet communication wiring from the camera 110 with thestepped-down power (such as 5 VDC) being brought into the processor 110through the input/output port 122 (e.g., a serial connector port).

[0040] Turning now to the portable field processor 110, the system 100is uniquely configured such that the speed of the vehicle 134 can beaccurately determined and an image captured with the detector 130 andcamera 140. This data is downloaded to the portable field processor 110,which can be removed or detached from the system 100 and easily carriedover to the vehicle 134 by a system operator to display the capturedimage with the determined speed to the vehicle operator. To achievethese and other functions, the processor 110 includes an input/outputport 122 for communicating with the detector 130 and camera 140. Theport 122 (e.g., an RJ45 socket) may be configured with a Compact Flashnetwork card, such as those available from Socket (e.g., a Socket, partnumber EA2902-139 Ethernet card), that in one embodiment is an Ethernetcard selected to provide 10BaseT communications with the camera 140.Preferably, the communication cable from the port 122 is ruggedized suchthat there is no connector to reduce the chance of a communicationmalfunction during field operations. Of course, the cable connectionsdiscussed and illustrated may be replaced with infrared (IR) linksbetween the processor 110 and one or both of the camera 140 and thedetector 130.

[0041] The processor 110 is preferably a small, handheld computer deviceor palmtop computer that provides portability and is adapted for easymounting (as discussed with reference to FIGS. 3 and 4). For example,any of a number of personal digital assistants (PDAs) may be utilizedfor the processor 110. As illustrated, the portable field processor 110includes a display and input/output screen 112 for use by the operatorin displaying an image and speed and range information to an operator ofthe vehicle 134.

[0042]FIG. 2 illustrates one embodiment 200 of a screen shot displayedon the display 112. The captured image includes an image of the vehicle134 and in this embodiment, the captured image has been processed by theprocessor 110 to zoom in or enlarge the portion of the captured imagethat shows the license plate 204 of the vehicle 134. The collected speedand range data and other operator-entered data (e.g., capture sessionparameters) are shown in an information section 208 of the screen 112 toprovide quick verification that the speed determined has been matched tothe correct vehicle 134.

[0043] Operation of the processor 110 to process the captured image isdiscussed below with reference to FIG. 6, and preferably includes theability to select portions of the captured image received from thecamera 140 for modification (e.g., to show clearly the license plate 204and/or the face of the vehicle operator). While many screen or displaytechnologies may be employed, one embodiment uses a reflective TFTscreen that uses sunlight for illumination to enhance outdoorperformance. The display 112 is used during operation to enter data(such as camera operating parameters and capture session parameters) andmay use stylus, touch screen, and keyboard functions commonly availablewith PDAs for entering and manipulating data (e.g., selecting items inmenus).

[0044] The processor 110 includes a central processing unit (CPU) 114,such as a 71 MHz MIPS R4000 or a 206 MHz Intel Strongarm 32-bit RISCprocessor, to perform the logic, computational, and decision-makingfunctions of the field processor 110 including interpreting andexecuting instructions. Memory 120 is provided for use during softwareexecution and for storing digital image files from the camera 140, speedand range information from the detector 130, and capture sessionparameters entered by an operator. In one embodiment, memory 120comprises 24 or more MB memory with 8 MB for program execution and theremaining 16 MB for data storage. An operating system 116 is provided tomanage the basic operations of the field processor 110 and in apreferred embodiment is the Windows™ CE 3.0 or newer operating systemavailable from Microsoft, Inc., Bellevue, Wash. that is configured tosupport UDP protocol for communicating with the detector 130 and camera140.

[0045] A system coordinator 118, e.g., operating software, is providedto coordinate the activities of the system 100. The system coordinator118 preferably is configured to allow an operator of the processor 110to set and modify system operating parameters, to browse previouslycaptured images, and to capture new images of vehicles 134. Numerousprogramming languages may be utilized, and in one embodiment, the systemcoordinator 118 is written in Visual C++ and compiled for the MIPS orStrongArm processor 114 and the specific operating system 116 (e.g.,Windows™ CE).

[0046] As noted earlier, the combination of a digital camera 140 and alaser speed detector 130 with digital data output significantlysimplifies the act of combining the speed and range data (and capturesession data input by an operator) with the digital image file from thecamera 140. This is a large improvement over prior art devices thatutilized video-based image capture and then employed a processing hungryand/or time consuming and complex series of steps to overlay the digitalinformation over a captured frame of the video image of a vehicle.Additionally, synchronization of the operation of the detector 130 andcamera 140 is simplified by the inclusion of digital photographytechnology in the system 100. Synchronization is important to accuratelymatch captured images with determined speed and range data.

[0047] In one embodiment, the system coordinator 118 achieves thecombination of the speed data with the image by inserting the speed andrange data into the digital image file header. Alternatively, thecombination of data may be completed by and at the digital camera 140.In this embodiment, the laser speed detector 130 is communicativelylinked to the camera 140 to receive operating instructions (e.g.,range-gate information) from the processor 110 as well as for passingthe determined data to the processor 110 via camera 140.

[0048] In addition to the speed and range data, a number of otheroperating parameters and capture session data (such as that illustratedin the screen portion 208) may be inserted in the image file header whenthe image file is processed and then stored in the memory 120 by thesystem coordinator 118. In one embodiment, the following information isstored in the image file header: (a) date (which is preferablyautomatically updated by the processor 110); (b) time (preferablyupdated automatically by the processor 110); (c) operator name (enteredby system 100 operator using a setup screen on display 112); (d)operator ID; (e) capture location (entered by operator using setupscreen indicating location for monitoring vehicles 134); (f) determinedspeed (provided by the detector 130); (g) distance (provided by thedetector 130); (h) speed limit (entered by operator using setup screen);X and Y crosshair positions (automatically entered during the alignmentprocess to show detection point of detector 130); and camera ID (enteredby operator and may include camera 140 serial number).

[0049] The systems coordinator 118 preferably allows the operator to setdifferent modes of operation of the system 100 to selectively storechosen images. In one mode of operation, the operator may select “all”which indicates that during a capture session all speed data forvehicles determined to being going equal to or above the captured speedare stored in a log file in memory 120 for statistical or other uses.The “all” setting may be useful for automated and non-monitoredoperation of the system 100 (such as setting up the system 100 at alocation for a period of time to monitor general traffic patterns andthen retrieving the system 100 or the memory 120 at a later time)

[0050] To reduce the number of image files (with added headerinformation) stored in memory 120, the operator may enter captureparameters such as a capture level that indicates the amount over theentered speed limit that should be captured. For example, the capturelevel may be set at 0 mph, and all vehicles 134 determined to be movingat a speed above the entered speed limit are captured. More preferably,a capture level such as 5 or 10 mph is entered to reduce the number ofimage files captured, processed, and stored in the processor 110 but yetto capture the vehicles 134 that are exceeding the entered speed limitby a level that indicates a citation or ticket should be issued. Thismode of operation is suitable for both unmonitored operation and formonitored operation (i.e., in which an operator monitors operation withthe capability of stopping a capture session to process and display animage to a particular vehicle operator).

[0051] Referring again to FIG. 1, the system 100 may include a fieldprinter 150 to allow the processor 110 to transmit an image print fileto the printer 150 to print screen images or other files in the field.For example, a thermal printer can be connected to the serial port ofthe processor 110 (or to the field processor housing 310, discussedbelow). Additionally, the system 100 may include a base station 160 incommunication via link 156 (a wired or wireless link that may include adirect connection such as by taking the processor 110 to a home officecontaining the base station 160 or a communications network such as theInternet) to the portable field processor 110. The base station 160 mayinclude one or more computer systems configured with software andprocessing components to enable the base station 160 to access andprocess the image files in memory 120 (or alternatively, the memory 120may be removed and taken to the base station 160). This enables anoperator of the base station 160 to browse the image files or to sortthe files based on capture sessions and/or speeds (or speed to speedlimit differentials) for creation of citations or tickets.

[0052] According to a preferred embodiment of the invention, the basestation 160 includes software and processing capacity to be able toprocess the digital image files to enhance the images to improve claritywithout modifying the original files. New screen images are created thatmay include enlarging selected portions of the image (such as thelicense plate area or operator area of the vehicle 134) and changing thecontrast of the image to provide a higher quality picture of the vehicle134. The base station 160 can then print the enhanced or unenhancedimage with all or select portions of the embedded text using anysuitable printer.

[0053] According to another feature of the illustrated system 100, avehicle classification sensor 170 is provided that is configured todiscriminate between different classifications of vehicles. In manysituations, governments enforce two or more different speed limits. Forexample, in the United States, a 65 miles per hour (mph) speed limit maybe enforced for vehicles under a certain height, weight, or axle number(typically, called private vehicles) while in the same location, a 55mph speed limit is enforced for vehicles over a certain height, weight,or axle number (typically, called commercial vehicles). In theselocations, it is useful to first differentiate or classify the vehiclesinto the classifications used to set and enforce the differing speedlimits and then to only capture those that are meeting or exceeding thespeed limit (e.g., capture level). Without this ability, the vehiclesviolating the lower speed limit are typically not captured or a largeamount of manual processing is used to eliminate all the vehicles notspeeding when the lower speed limit is used as the capture level.

[0054] Referring to FIG. 1, the system 100 is shown to include a vehicleclassification sensor 170 configured for sensing a characteristic of thevehicle, such as height, weight, axle number, and the like. The sensor170 may be configured to transmit a signal providing this characteristicdata to the input/output 122 of the portable field processor 110(automatically or upon request from the processor 110). In a preferredembodiment, the vehicle classification sensor 170 is configured todetermine the classification of the vehicle and to then transmit thevehicle type information to the portable field processor 110. Thisvehicle classification signal may be sent directly or the informationmay be concatenated with the laser speed detector 130 speed data (e.g.,the combined data string may include vehicle speed, vehicle range fromdetector 130, and vehicle type).

[0055] While many vehicle sensor configurations may be utilized topractice this feature of the invention, the illustrated sensor 170 isuseful for sensing the height of the vehicle 134. In this regard, thesensor 170 typically is mounted and aligned within the system 100 tosense when a vehicle 134 is at or above a height limit, such as 6 to 9feet (i.e., whatever vehicle height is used by the government forsetting the lower speed limit).

[0056] The portable field processor 110 then processes the vehicle typeinformation along with the vehicle speed data to determine if an imageshould be captured. For example, the portable field processor 110 may beconfigured to first identify the vehicle type or classification and thenretrieve from memory 120 a vehicle speed limit for the classification.In a more preferred embodiment, the operator of the portable fieldprocessor 110 inputs capture levels for each possible vehicleclassification. In this embodiment, once the processor 110 identifiesthe vehicle classification from the signal from the sensor 170, theprocessor 110 compares the received vehicle speed with the appropriatecapture level to determine if an image should be captured. In thismanner, the system 100 enables effective and accurate vehicleclassification and capture of speeding vehicle images in locationshaving more than one enforced speed limit.

[0057] According to another useful aspect of the system 100, theportable field processor 110 may be configured to transmit wirelesssignals to remote field locations to enhance speed enforcement. Inpractice, the portable field processor 110 and the digital camera 140,and the detector 130 may be positioned to capture images of speedingvehicles at a first location on a road while the enforcing officer maybe positioned at a second location remote from the processor 110, suchas 100 to 200 meters or further down the road from the processor 110.With this positioning, the enforcement officer can be informed with asignal from the processor 110 of an approaching speeding vehicle 134 andmore importantly, be provided with the combined vehicle speed data andimage file for use in stopping and ticketing the vehicle 134.

[0058] In this regard, the portable field processor 110 is shown in FIG.1 to include a wireless output 174 for transmitting a wireless signal176 to a remote field receiver 180. As discussed above, the wirelesssignal 176 preferably includes the combined speed data and image file(explained in detail previously). The remote field receiver 180 may beany wireless device configured for receiving a wireless signal, and inone embodiment, is a device similar to the portable field processor 110that is useful for processing and displaying the captured image andspeed data to an operator of a vehicle 134. A thermal printer may alsobe used at the remote location to print out hard copies of the image andspeed data. A number of well-known wireless network devices andtechnologies can be utilized for the wireless output 174. Similarly, anumber of digital wireless protocols may be used, such as CDMA, GSM,iDEN, CDPD, and Bluetooth.

[0059] Referring now to FIGS. 3-5, one embodiment of the speedmeasurement and image capture system 100 is illustrated that clearlyshows the compact and portable nature of the system 100 that isachieved, at least in part, through the combined use of the digitalcamera 140 and the portable field processor 110. As shown, the system100 can readily be mounted on and supported by a standard tripod 330(such as a photographer's tripod). Due to the lightweight and compactcharacteristics of the system 100, the system 100 alternatively can besimply hand-held by an operator, be mounted on a number of standarrangements besides the illustrated tripod 330, or be mounted directlyto a vehicle with the use of a receiving bracket (not shown) attached tothe vehicle.

[0060] As shown in FIGS. 3-5, the system 100 is mounted to the tripod330 utilizing system mounting bracket 320 in a manner that balances thesystem components to enhance stability. Additionally, the mountingbracket 320 includes a quick release plate 322 that is configured toengage the tripod 330 such that the plate 322 can be mounted rapidly andoptionally fastened to the tripod 330 to lock the plate 322 in position.In the illustrated embodiment, the plate 322 is configured to slide intogrooves in the tripod 330 and fasteners can be inserted through holes inthe plate 322 to rigidly attach the bracket 320 to the tripod 330.

[0061] To distribute the weight of components and enhance stability, theillustrated bracket 320 is adapted to facilitate mounting of thedetector 130, the digital camera 140, and the field processor 110 (alongwith any protective housing 310) on the tripod 330 (or other supportstructure) such that the mounted system 100 is stable. Further, it ispreferable that the mounted system 100 remain relatively stable with orwithout the field processor 110, as a key feature of the invention isbeing able to remove the field processor from the system 100. Manyalternative arrangements can be envisioned for maintaining a stablemounting of the system 100 on a bracket 320, and these alternativemounting arrangements are considered within the breadth of thisdisclosure.

[0062] In the illustrated embodiment, the bracket 320 is configured suchthat the typically heavier detector 130 is mounted substantially abovethe quick release plate 322. This enhances the stability of the mountedsystem 100 by placing the heaviest component on or substantially on acentral axis of the tripod 330 (or on an axis passing through the centerof gravity of the tripod 330). The digital camera 140 is then mounted onthe bracket 320 adjacent a first side of the detector 130 and a fieldprocessor housing 310 for housing the processor 110 is mounted on thebracket 320 adjacent a second side of the detector 130. Thisconfiguration provides weighted stability for the mounted system 100with the processor 110 positioned within or removed from the housing310.

[0063] Additionally, mounting the camera 140 to the same bracket 320 asthe detector 130 facilitates mechanical alignment of the two componentssuch that captured vehicle images more readily correspond to thevehicles 134 for which speed is detected. When the camera 140 isattached to the bracket 320 (or the portion or arm of the bracket 320that is supporting the detector 130), the camera 140 can be adjustedvertically and horizontally to be substantially parallel with thesighting device of the detector 130. Alignment can be achieved by firstsighting the detector 130 on a stationary object and then secondsighting the camera 140 on the same object (or in opposite order). Oncemechanically aligned, the two devices 130 and 140 are preferably lockedin place, such as with fasteners, such that alignment is only requiredupon initial set up. Final alignment (or refined camera targeting) ofthe camera 140 is preferably achieved with the systems coordinator 118of the processor 110 which can operate to position digital imagecrosshairs onto a specific feature of a sighted object. The crosshairsindicate the detection location of the detector 130 on an image capturedby the camera 140.

[0064] As discussed with reference to FIG. 1, the detector 130 andcamera 140 communicate with the portable field processor 110. As shown,the detector 130 includes a communication port 520 and the camera 140includes a communication port 530 (although in some applications IRlinks may be utilized). Standard communication cables (not shown) arethen used to connect the detector 130 and camera 140 to thecommunication port 502 (illustrated as a serial port) of the fieldprocessor housing or enclosure 310. The portable field processor 110(not shown in FIGS. 3-5) is positioned or plugged into the base 312 ofthe housing 310 to provide for communication with the detector 130 andcamera 140 (as discussed with reference to FIG. 1). A protective cover314 is provided that can be open, such as with hinges, to allow accessto the interior portion of the base 312 for insertion and removal of theprocessor 110 during operation of the system 100. In this manner, theprocessor 110 is protectively housed in the housing 310 with docking forcommunication with the detector 130 and camera 140 but yet can readilybe detached or unplugged from the housing 310.

[0065] The protective cover 314 includes a viewing window 318 to allowthe cover 314 to be closed to protect the processor 110 from weather anddust during field use of the system 100. To enter data, the cover 314 istypically opened to provide access to the display 112 of the processor,and for use with many processor 110 configurations a stylus holder 316is provided on the side of the base 312 to hold the stylus-type datainput tools provided with palmtop computers and PDAs. An optional coverlocking knob 514 is provided to lock the cover 314 in the closedposition.

[0066] Preferably, the camera 140 also provides charging power to theprocessor 110. As illustrated, the camera 140 includes a power outletport 534 which is connected with a cord (not shown) to the power supplyport 124 of the housing 310 and processor 110. In another preferredembodiment, the trickle charging power is provided over thecommunication cable and fed into the processor 110 over a standardcommunication port (e.g., serial port 502). In this embodiment, only onecable is needed to transfer data (i.e., digital image files andparameter data) between the camera 140 and the housing 310 and totransfer power from the camera 140 to the housing 310. The single cablewould connect the communication port 530 of the camera 140 to thecommunication port 502 of the housing 310 (which in turn, is connectedto the communication port, typically a serial port, of the processor 110when the processor 110 is docked within the housing 310). Also, asdiscussed with reference to FIG. 1, in some embodiments a shortcommunication cable (not shown) is used to communicatively link thedetector 130 to the camera 140 to reduce the length of cabling required.In this embodiment, the processor 110 exchanges data with the detector130 through the camera 140 communication cable and port 530.

[0067] Referring now to FIG. 6, operation of the speed measurement andimage capture system 100 will be discussed to provide a furtherunderstanding of the unique features of the invention. At 610, theoperation process 600 is started with initial set up of the portablesystem 100. Initial set up may involve numerous steps such as themounting of the system 100 on the bracket 320 and/or tripod 330, butgenerally involves selecting a capture session location in which tomonitor vehicle traffic (such as adjacent a road within the system'stargeting area and with the sun striking the rear of the detector 130and camera 140 to control glare and to better illuminate license plates)and setting up, connecting, and powering up the components of the system100. A portion of a road may be targeted and vehicles automaticallytargeted and/or captured as they cross into the capture area or targetline or alternatively, an operator may target manually specific vehiclesby changing the position of the system 100 (e.g., turning the system 100on the tripod 330).

[0068] At 614, the operator is requested via a menu or other data entrydevice on the display screen 112 of the processor 110 to select anoperating mode. A number of operating modes may be included foroperation of the system 100 such as a browse mode that allows theoperator to view previously captured images and a system mode thatallows the operator to enter or modify system settings (such asadjusting the camera 140 settings, the detector 130 settings, the imagesto be logged or stored (such as only vehicles above a capture limitindicating speeding) and the like). If these modes are selected, oncethe operator is finished entering information or viewing (and processingand printing) images, the process 600 ends at 618. To capture newvehicle images and speeds, the operator at 614 selects capture mode (orcontinue previous capture mode) and at 618 the process 600 is continued.

[0069] At 622, the operator is requested via a data entry screen on thedisplay 112 to enter capture session information or parameters. Aportion or all of these parameters will then be inserted by the systemcoordinator 118 into the captured image file (such as in the header of aJPEG file) for inclusion in the captured image files stored in memory120 and/or shown to vehicle operators. A wide variety of parameters maybe included but in one embodiment, the parameters include an operatorname, an operator ID, a capture session location, the posted speed limitfor the location, the capture level or capture speed limit (i.e., aspeed value for which the system 100 will capture an image when thedetermined speed by the detector 130 is greater than or equal to thespeed value), weather conditions (which in some embodiments is used bythe system coordinator to automatically determining camera 140 settingssuch as camera gain), and the camera 140 serial or identificationnumber.

[0070] At 626, the capture session is begun. The system 100 is eitherpositioned to automatically detect vehicles 134 that enter a target areaor the operator of the system 100 may move the system 100 to targetparticular vehicles 134 (such as by turning the upper portion of thetripod 330). When a targeted vehicle's speed and distance from thedetector 130 are determined by the detector 130, this information istransmitted to the processor 110 (e.g., via a communication connectionsuch as RS232). The system coordinator 118 compares the determinedvehicle's speed with the entered capture level or capture speed limitfor the capture session. If the determined speed is less than thecapture speed limit, no image is taken, i.e., the camera 140 is notoperated to capture an image (unless all images and speeds are beinglogged for monitoring traffic patterns). If the determined speed isequal to or greater than the capture speed limit, the system coordinator118 of the processor 110 transmits an operational signal to the camera140 to trigger the camera 140 to capture an image of the vehicle 134.The camera 140 retrieves the current digital image file from its memoryand downloads the digital image file (e.g., a JPEG file) via theEthernet or other connection to the processor 110.

[0071] The image capture step 626 may also include first classifying thevehicle 134 into classifications, such as private and commercial, usedby a government agency for establishing two or more speed limits (e.g.,capture levels). This classification is performed by the processor 110or the vehicle classification sensor 170 based on detected informationby the sensor 170 (such as vehicle being above a certain height, above aweight limit, or having more than a set number of axles). The processor110 then acts to first retrieve or identify the classification of thevehicle and then compare the vehicle speed with the appropriate capturelevel.

[0072] Within the image capture process 626, it is important tosynchronize image capture by the camera 140 with detection of speed bythe detector 130. Typically, laser speed detectors 130 operate on ameasurement cycle as measured from the start of individual laser shotsor transmissions to the calculation of the speed and distance. A typicallaser speed gun or device may have a measurement cycle of about 300milliseconds to 400 milliseconds (with some devices having shorter andsome longer cycles). The speed and distance data are transmitted to theprocessor 110 at the end of this measurement cycle. Hence, the time fromthe start of the measurement process to the export of the data is atleast about 300 milliseconds and typically less than about 400milliseconds.

[0073] To achieve synchronization, the digital camera 140 is preferablyprogrammed such that the image is not taken for a time period greaterthan the shortest portion of the detector measurement cycle (i.e., about300 milliseconds for the above illustrative examples). Also, a maximumlatency time (i.e., time between triggering signal received at camera140 and taking picture) is selected such that the detector 130 wouldmost likely not have been aimed at a new target or automatically trackedon a new target vehicle. In one embodiment, a maximum latency time of200 milliseconds is utilized, but it is understood by the inventors thatsmaller and larger latency times may be selected to provide acceptablesynchronization of the camera 140 and detector 130. In this embodiment,an image capture window is established that begins at about 300milliseconds before the end of the measurement by the detector 130 andthat ends at about 200 milliseconds after the trigger signal to thecamera 140.

[0074] With this image capture window established, the camera 140 ispreferably programmed in combination with operation of the systemcoordinator 118 (which transmits the camera trigger signal) such thatthe camera timing cycle coincides with the image capture window to placean image frame containing the vehicle 134 for which speed was measuredwithin the memory of the camera 140. The camera timing cycle in oneembodiment is approximately 200 milliseconds with the image frame beingplaced in memory as early as 100 milliseconds prior to the end of speedmeasurement by the detector 130 and as late as 100 milliseconds afterthe end of speed measurement.

[0075] This timing cycle is obtained by the systems coordinator 118adding a time delay, such as 100 milliseconds, from the time thedetector 130 completes and transmits the speed measurement to theprocessor 110. Another phase of the timing cycle is established by thecamera 140 which updates a compressed image into alternating buffersperiodically, such as every 200 milliseconds. If the camera triggersignal is received just before the next update, the image would be 200milliseconds old (or 100 milliseconds prior to the end of the speedmeasurement). Conversely, if the camera trigger signal is received assoon as the buffer is updated, the image is frozen immediately (or 100milliseconds after the end of the speed measurement). Of course, thoseskilled in the art will understand that the camera timing cycle, theimage capture window, the timing of the camera trigger signal, and thespeed measurement cycles will vary with particular components chosen forthe system 100 and with the programming and operating setting of eachcomponent. These variations are acceptable in practicing the inventionas long as the image capture and speed determination events can beadequately synchronized such that the same vehicle is captured in animage file and is targeted for speed determination.

[0076] As discussed with reference to FIG. 1, a significant feature ofimage capture is the combination of the image file from the camera 140with the speed and distance data from the detector 130 and other systemand/or capture session parameters. Typically, the data combination iscompleted at the processor 110 by the system coordinator 118 whichfunctions to write or insert the speed and distance information into theheader of the image file (e.g., JPEG-formatted file). The systemcoordinator 118 also writes select portions of the system parameters(such as time and date) and capture session parameters (such aslocation, speed limit, and operator ID) into the digital image fileheader. Generally, after the digital image file header is modified orthe information is otherwise appended to the digital image file, themodified digital image file is displayed on the display 112 of theprocessor 110 for viewing by the operator.

[0077] In one preferred embodiment, the operator at 626 can operate theprocessor 110 to zoom in or enlarge select portions of the displayedimage file. For example, the operator may select the license plateportion or the driver's side of the windshield to enlarge one of theseportions of the displayed image. Various image enhancing tools may alsobe provided in the processor 110, and if included, the operator canenhance the image by altering the displayed contrast, brightness, andother characteristics useful to make a clearer and sharper image.

[0078] In some applications, the system 100 is allowed to operate for aperiod of time automatically capturing images of vehicles (all or onlythose above the capture limit) and combining speed and distance imageand select system parameters with the digital image files. Thesecaptured and modified digital image files are then stored in memory 120for later viewing and processing. This later viewing and processing canoccur in the field via the processor 110 and/or the optional fieldprinter 150. Alternatively, at 638, the images stored in the memory 120(i.e., capture session data) are downloaded from the processor 110 to abase station 160. The downloading may be completed remotely over acommunications network 156 or directly by interconnecting the processor110 to a computer system within the base station 160 or by removing thememory 120 for use in the base station 160. At the base station 160, thecombined image files can be sorted by determined speeds, bydifferentials between determined speeds and speed limits, by location,or by other information appended to the image file (e.g., inserted inthe image file header). The images may also be processed to enhancepicture quality and to enlarge select portions of the image. Theelectronic or hard copies of the processed images may then be used aspart of a citation or ticket transmitted to the vehicle owner oroperator.

[0079] Alternatively, according to a significant feature of the system100, the portable field processor 110 may be used by an operator toprovide proof in the field that a vehicle was violating a posted speedlimit. At 630, the operator may interrupt an active capture session. Forexample, an operator may observe the displayed image on the display 112of the processor 110 and when a speeder is displayed (above capturelimit or by visual identification by the operator), the operator maystop the capture session to pull over the vehicle and issue a ticket.Alternatively, the system coordinator 118 may be adapted to provide anaudio and/or visual alarm when a vehicle is detected to be driving at orabove the capture limit and its image is captured. At this point, theoperator detaches or unplugs the processor 110 from the housing 310 andcarries the processor 110 to the stopped vehicle. The operator candisplay the captured image with combined data to the vehicle operator onthe display 112.

[0080] Alternatively, at 630, the captured speed data and digital imagemay be transmitted to a receiver operated by a remotely positioned fieldoperator (law enforcement officer). The field operator can then processthe information with their equipment, such as another portable fieldprocessor 110, and stop an approaching vehicle shown in the capturedimage. The field operator can then display the image to the operator ofthe vehicle 134 as described above.

[0081] The operator of the system 110 may process the captured image toenlarge the license plate or the driver's face and to enhance theclarity of the displayed image. When the operator has completed usingthe processor 110 to prove a vehicle's speed to a driver, the operatordocks the processor 110, located in the housing 310, to its bracket. At634, a new capture session may be begun (returning to step 610) or theprevious capture session can be resumed without having to reentercapture session parameters. After the session is completed, the capturesession data can be downloaded to the base station at 638 for furtherprocessing.

[0082] In one embodiment, a data security process is performed by thesystem coordinator 118 prior to writing the combined data image file tomemory 120 to ensure that the image and/or speed data is not alteredbetween the time it is collected and the time it is used in a citationor as evidence. A number of security processes may be utilized toindicate whether a data file has been altered. For example, the systemcoordinator 118 may perform a check sum on the data with a seed numberin the header of the combined speed data and digital image file, encryptthe check sum, and append the encryption into the header of the file.Then when a saved image file is opened, it is first verified as notbeing altered by removing the encrypted check sum and replacing thecheck sum with a seed number. The same type of check sum is run on thefile and the new check sum is encrypted. The two encrypted check sumsare then compared to determine if alteration has occurred. Of course,numerous other security processes may be utilized to reduce the risk ofdata modification but the exemplary method has proven effective and isdetailed enough to detect an alteration as small as inverting speeddigits (e.g., changing 75 mph to 57 mph). Note, in some embodiments,security is further enhanced by verifying with the processor 110 thecheck sum output directly by the laser speed detector 130 with anexpected check sum value.

[0083] In addition to enforcement of speed limits, it is desirable toprovide a system and method for identifying vehicles that violatetraffic signs and signals, such as stop signs, traffic lights, and otherpostings or traffic devices that require a vehicle to come to a stop ata particular location. Such signals may vary based on the traffic lawsof a country or locale, but in the United States, stop signs and trafficsignals are typically placed at corners where one road intersectsanother road. To comply with the posted stop sign, an operator of avehicle is required to come to a complete stop, i.e., a vehicle speed of0 mph, for a period of time. Similarly, a traffic light when showing ared light requires a vehicle operator to stop their vehicle until thetraffic light changes to show a green light. Other postings, trafficsigns, or signals may likewise require a vehicle to stop at a particularlocation, such as certain railroad crossing signs or signals (e.g., atblind crossings) that require all vehicles to stop prior to crossingover the railroad tracks.

[0084] For these and other stop “signs” (e.g., the use of stop signs inthis application is intended to include any and all devices used tocause a vehicle to stop such as printed stop signs, traffic lights,certain railroad crossing signage, and the like), it is desirable to beable to detect violations, i.e., vehicles that fail to stop, and tocapture enough information to create a valid citation for the violation(such as an image of the front or rear of the vehicle with a licenseplate and/or an image of the vehicle driver) as discussed with referenceto FIGS. 1-6.

[0085] In this regard, FIG. 7 illustrates a stop sign (or trafficsignal) enforcement system 700. In the system 700, many of thecomponents of the system 100 of FIG. 1 are included and provide similarfunctionality. For example, the laser speed detector 130 is utilized todetect a speed of a vehicle 134 located a distance from the detector 130(such as a range distance, d_(RANGE)) as discussed with reference toFIG. 1 and the camera 140 functions to capture an image of the vehicle134 in response to a capture or trigger signal from the portable fieldprocessor 110.

[0086] The portable field processor 110 is configured similarly as inthe system 100 but further includes a stop sign enforcement module 710(which may be integrated with system coordinator 118 or may be providedby configuring the system 700 and processor 110 and its softwareaccording to the following description) that typically includes theoperating software, program, and/or routines used by the processor 110in determining when a stop sign violation has occurred and in response,initiating an image capture or trigger signal by the system coordinator118 to the digital camera 140. As with the system 100, the detector 130and camera 140 are preferably synchronized such that an image capturedby the camera 140 is of a vehicle 134 that is determined to be travelingat a detected speed (e.g., a speed over a capture speed threshold).

[0087] Because certain functionalities are not required for stop signenforcement, some components of the system 100 may be left out of thesystem 700 (or if one unit is used and marketed for all functionalitiesof the invention, these components can be provided but not activelyutilized during stop sign enforcement). For example, the wireless output174 and remote field receiver 180 typically would not be required in thesystem 700 as the enforcement session data is typically downloaded to abase station 160 (but in some cases, the session data may be transmittedusing a wireless output, such as device 174, to the base station 160such as when the processor 110 is relatively permanently positioned at alocation for stop sign enforcement). The vehicle classification sensor170 is not shown in system 700 as generally stop sign laws apply equallyto all vehicle types (but may be included for stop signs that requirecommercial vehicles, including busses, to stop but not private vehicles,such as at some railroad crossings). Hence, the system 700 may besimplified in functionality and configuration compared to the system100. Generally, prior to operation, the system 700 is positioned withina vehicle, such as a van or other vehicle, or other support andprotective enclosure (such as a shed or portable trailer) that is itselfpositioned nearby a particular stop sign within the effective range ofthe detector 130 and camera 140. The system 700 may be positioned asshown in FIG. 7 behind the stop sign 720 so as to capture a frontalimage of the vehicle 134, or alternatively, may be positioned in front(e.g., down the road on the side of the sign 720 displaying the print,symbols, or lights) of the stop sign 720 so as to capture an image ofthe rear portion of the vehicle 134.

[0088] To fully explain operations of the system 700 and its uniquefeatures, it may be useful to describe the system 700 in conjunctionwith one exemplary operating procedure 800 shown in FIG. 8. Theoperating process 800 is started at 805 generally by providing the stopsign enforcement module 710 in the portable field processor 110 orotherwise providing the software in the system coordinator 118 (orelsewhere) to perform the processing functions described within theoperating procedure 800. At 810, the portable system 700 including theprocessor 110, the detector 130, and camera 140 are set up in the fieldto detect stop sign violators (e.g., violators of traffic signals thatrequire stopping a vehicle) and capture information for proving suchviolation of the posted signage. The initial set up, as with step 610 ofprocess 600 in FIG. 6, may involve a number of steps such as themounting of the system 700 on the bracket 320 and/or tripod 330 or othersupport structure and generally involves selecting an enforcement siteor location at which to monitor vehicle traffic relative to a particularstop sign 720. Again, although FIG. 7 illustrates one location for thedetector 130 and camera 142, other locations may be utilized to practicethe method 800 including, but not limited to, positioning the detector130 and camera 140 in front of the sign 720 typically on the same sideof the lane 724 as the sign to have a line of sight to the front of thesign 720 and the rear of vehicles 134 in the enforcement window 736adjacent the sign 720 in the lane 724.

[0089] Once an enforcement site is chosen, the system 700 is generallypositioned adjacent a road (or lane 724 of a road) a particulardistance, d_(RANGE), from the stop sign, such as along (e.g., downtraffic or up traffic) the road with an unobstructed view of the back(or front) of the stop sign 720 and the lane 724 adjacent the stop sign720, i.e., where a vehicle 134 is required to stop for a period of timeand labeled an enforcement or measurement window 736 in FIG. 7. The setup location for the portable field processor 110, laser speed detector130, and camera 140 is determined by line of sight and distanceconsiderations given optimum conditions associated with normal laserdetector 130 and camera 140 usage. Typically, the distance or range,d_(RANGE), is dictated by the optimum range of the camera lens 142 toensure clear and identifiable images for reading license plates incaptured images and subsequent citation or ticket creation at 890.

[0090] At 820, the operator of the system 700 is requested via a menu orthe like on the screen 112 (or other input point or feature) of theprocessor 110 to select an operating mode. The modes may include thosediscussed relative to process 600 and step 614 and, in the system 700,further include a stop sign enforcement mode (or the “mode” may beimplied by an operator configuring the system 700 according to themethod 800 with no actual mode selection provided to an operator). Thestop sign enforcement mode may coincide with a standard automatic modefor some units in which images are automatically captured along withspeed detector data when a capture speed threshold (or capture level) isexceeded except that the stop sign threshold is typically set much lowerthan previously discussed capture levels or speeds, i.e., a set amountin excess of a posted speed limit.

[0091] At 830, the system coordinator 118 determines whether the stopsign enforcement mode was selected in the menu or otherwise at 820 (oragain, the “mode” may be implied by the settings selected by operator).If a different mode is selected, operation 800 continues at 840 withtransfer of the process or operations by the system coordinator 118 tothe process 600 and capture mode query 618. If the stop sign enforcementmode is selected and identified at 830, operation 800 of the system 700is continued by operation of the coordinator 118 in conjunction with thestop sign enforcement module 710 of the portable field processor 110.More particularly, the processor 110 is programmed for a particularenforcement window 736 and speed threshold.

[0092] At 850, ranging is performed for the system 700 for theparticular enforcement site, which may be behind the sign 720 as shownin FIG. 7 or in front of the sign 720, which dictates the positioning ofthe detector 130 and camera 140 relative to a stop sign 720. The rangingdistance, d_(RANGE), is generally measured from the stop sign 720, suchas the back side (or front side) of the stop sign, to the laser speeddetector 130 and/or the lens 142 of the camera 140. Ranging at 850 isperformed by aiming the laser speed detector 130 at the back (or front)of the stop sign 720 (or to a post or other portion of the sign orsignal) being monitored by the system 700. The laser speed detector 130preferably can then be set to detect speeds of vehicles 134 with thisdetermined distance, d_(RANGE), from the detector 130 and to displaythis distance, d_(RANGE), for entering into the processor 110 as anenforcement parameter at 860 (e.g., programmed into the processor 110 asthe measurement distance for downloading to the base station 160). Thespace or area adjacent the stop sign 720 in the lane 724 can be thoughtof or labeled the enforcement window or range 736 that is adjacent andgenerally behind the sign 720 and is the point or area where a vehicle134 will violate stop sign laws (or where an infraction will occur).

[0093] Typically, the laser speed detector 130 is operable for a windowor set of distances beyond the measurement distance, d_(RANGE), and willoperate effectively for measuring speeds within this measurement,capture, or enforcement window 736. For example, the detector 130 may beconfigured to have a 10-foot or larger (or smaller) window 736 such thatif the measurement or ranging distance, d_(RANGE), was determined to be60 feet the laser speed detector 130 would target vehicles 134 that are60 to 70 feet from the detector 130 and ignore all targets or vehicles134 outside this measurement or capture window 736. This enables thedetector 130 to measure the speed of a single target (as 2 vehiclestypically will not fit within a single 10-foot enforcement window 736)within the enforcement area in the lane 724 in front of the sign 720. Asdiscussed previously with respect to system 100, preferably the camera140 is selected to have a range that coincides with the enforcementdistance, d_(RANGE), and more particularly, the lens 142 isautomatically or manually adjusted to focus at a distance correspondingto the enforcement distance, d_(RANGE), or within the correspondingenforcement window 736 adjacent and in front of the sign 720 in the lane724. Note, the enforcement distances and sizes of the window 736 may bevaried in practicing the invention with the examples above provided forillustration purposes and not as limitations to the invention.

[0094] At 860, the operator of the system 700 is requested via a dataentry screen 112 to enter stop sign enforcement session parametersincluding a capture speed threshold. The parameters may vary but willtypically include information useful for inclusion in the captured imagefile (such as in the header of a JPEG file and, for example, seeinformation portion 208 of display 200 in FIG. 2) and/or for use inpreparing or supporting a ticket or citation prepared based on adetected stop sign violation. This information may include operatorname, an operator ID, an enforcement site and stop sign location, thetype of sign being monitored, weather conditions (which may effectcamera 140 settings/operation), the camera 140 and/or detector 130identifiers, and, significantly, the capture or enforcement speedthreshold (or capture level).

[0095] Also, at 860, the system 700 is set to automatically capture(i.e., placed in an auto-capture mode) violators of the monitored stopsign 720. According to one feature of the system 700, the stop signenforcement module 710 (or system coordinator 118 or other software orhardware in processor 110) is adapted for determining when a vehicle 134violates the stop sign law (i.e., runs the stop sign 720) by comparing aspeed of the vehicle 134 detected by the laser speed detector 130 to acapture speed threshold. The capture speed threshold may be a defaultvalue (such as up to 10 mph or more) or may be entered by the operator860 to comply with policies, regulations, and/or laws in force at theenforcement site (i.e., to comply with local, county, state, and/ornational standards or rules). Typically, a capture speed threshold willbe input at 860 based on standards set by the agency for which theoperator is working and will be set to establish reasonable and fairthresholds for identifying violators of a stop sign 720, e.g., a vehicletraveling at 10 mph or higher is unlikely to be able to stop within theenforcement window 736.

[0096] Once the capture speed threshold is entered, the system 700 canbe operated to monitor the stop sign 720 and automatically captureimages and data for violating vehicles 134. As part of 860, the laserdetector 130 is aimed at about the middle of the lane 724 and the system700 is instructed to or switched to an automatic capture mode (such asby selecting a button on a menu of display 112). This automatic mode ofstop sign enforcement involves continuous operation of the laser speeddetector 130 to detect vehicle speeds and, at least periodically, tooperate the synchronized digital camera 140 to capture images ofviolating vehicles 134 (i.e., vehicles 134 traveling at detected speedsabove the set or default threshold).

[0097] As discussed above with regard to FIGS. 1-6, the camera 140operates to capture images based on signals from the portable fieldprocessor 110. Preferably, the camera 140 operates in synchronizationwith the speed detection by the detector 130 and does so in one of themanners described for system 100. The camera 140 generally captures animage having a width, w_(CAPTURE), that preferably includes the stopsign 720 and the lane 724 but which may be narrower so as to capture allor a portion of the vehicle 134 in the lane 724. This enables the camera140 to capture an image of the stop sign 720 that is being violated andthe entire front or rear portion of the vehicle 134 (or at least thelicense plate of the vehicle 134), including the license plate and, insome cases, the windshield and image of the drivers of the vehicle 134when the system 700 is arranged as shown in FIG. 7 to capture frontalimages of vehicles 134. The camera 140 is preferably aligned with thedetector 130 to capture images corresponding generally with the speeddetection location, i.e., the enforcement window 736 relative to thesign 720.

[0098] The trigger signal for the camera 140 is initiated by the module710 based on a determination that the detected speed received by theprocessor 110 from the detector 130 is above the capture speedthreshold. In other words, the system 700 acts to identify stop signviolators based on a vehicle 134 not stopping. According to theinvention, a vehicle's failure to stop is determined by the vehicle 134being determined to be traveling above a threshold speed adjacent thestop sign 720 within an enforcement window 736 adjacent the stop sign720. A non-violating vehicle 134 (one traveling at a detected speedbelow or at the threshold) is assumed to be slowing down when enteringthe enforcement or measurement window of the detector 130 and thenstopping (or going 0 mph). Hence, a fair threshold is one that assumes arelatively rapid reduction of speed within the enforcement window toavoid capturing images of vehicles 134 that stopped at the sign 720 butstopped quickly or within a relatively short distance (i.e., the lengthof the enforcement window 736). In this regard, a “fair” threshold valueis generally in the range of 10 mph to 20 or more mph (at which speedsthe vehicle 134 most likely would not be able to stop at the sign 720)with more conservative thresholds being set at the posted speed limitsor percentages of the posted speed limits for the lane 724.

[0099] The following operating examples are provided to more fullydescribe operation of the system 700 in enforcing stop sign laws. In afirst non-limiting example, the capture speed threshold is set at 10 mphand the measurement distance, d_(RANGE), is determined to be 50 feetwith a 10-foot window 736. The car 134 approaches the monitored stopsign 720 and rolls into the front end of the enforcement window (i.e.,about 60 feet from the detector 130 and about 10 feet behind the stopsign 720) at a speed of 18 mph. The laser speed detector 130 functionsto detect the speed and transmit a signal to the processor 110 and stopsign enforcement module 710 (or system coordinator 118 or othersoftware/hardware of processor 110). The module 710 determines that thethreshold of 10 mph is exceeded and transmits a trigger signal to thecamera 140 which captures the image (such as by freezing its buffer ortaking a picture within its image timing cycle).

[0100] The camera 140 transmits the image of the vehicle 134 to theprocessor 110. The image and enforcement information along withparameters are saved in memory 120 as a single digital file (asdescribed in detail with reference to FIGS. 1-6) or as two or more filesthat are linked or otherwise matched to assure proper mating of images,enforcement information, and parameters. The single file or multiplefiles typically include an image of the vehicle 134 and its licenseplate and information for the file header including time and date ofviolation, a distance to the vehicle 134, and the detected speed of thevehicle 134. Note, again, the detector 130 and camera 140 may bepositioned in front of the sign 720 such that the system 700 acts todetect a violation, to capture an image of the back portion of thevehicle 134 and, in some embodiments, the front of the sign, andenforcement parameters.

[0101] In a second example, the measurement distance, d_(RANGE),determined in the ranging of step 850 is 60 feet, the measurement rangeof the detector 130 is 15 feet, and the capture speed threshold isentered at 860 to be 20 mph. When a vehicle 134 crosses the front (ordistal) end of the measurement or enforcement window 736 (i.e., about 75feet from the detector 130 and about 15 feet in front of the stop sign720 in the lane 724) going 15 mph, the vehicle 134 is determined not tobe violating the stop sign 720 and no image is captured. This isdetermined by the system 700 because the detector 130 targets thevehicle 134, determines the speed of 15 mph, and transmits acorresponding signal to the processor 110 and module 710. The module 710compares the detected speed to the threshold and determines that noviolation has occurred (or that the vehicle may stop at the sign 720)and does not transmit or initiate a trigger signal to the camera 140.Numerous other examples will be apparent to those skilled in the artwith varying capture thresholds, enforcement window sizes and locations,and positions for the detector 130 and camera 140.

[0102] At 870, the enforcement session is terminated, such as by anenforcement officer or an operator switching off power to the system 700or selecting a stop button on the display 112 or elsewhere on theprocessor 110. Termination can also be achieved by transmitting atermination signal from a remote device, such as a wireless transmissionfrom the base station 160. At 880, the enforcement session data inmemory 120 is downloaded from the processor 110. Typically, this isachieved by transporting the processor 110 (and, optionally, thedetector 130 and camera 140) to the location of the base station 160 andwiring the processor 110 to the base station 160. Alternatively, thedownloading may include removal of the memory 120 and then laterinsertion in the base station 160 for data transfer or include wired orwireless transmission of the data in memory 120 to the base station 160(or another system) for further processing.

[0103] Of course, the data and images in the memory 120 can be viewed onthe display 112 of the processor 110 by an operator prior to downloadingto determine if downloading is required or useful. In some embodiments,the module 710 is further adapted to track numbers of violators orimages in the memory 120, such as based on actual image numbers orpercentage of memory 120 being utilized. In these embodiments, themodule 710 (or other software/hardware in processor 110) may beconfigured to transmit an alarm or notification signal to the basestation 160, such as by a wireless output device (not shown), when acertain number of images have been captured or percentage of the memory120 has been utilized. Additionally, the module 710 or other componentsmay operate to shut down monitoring operations at this point to avoidoverwriting previously stored images. Automatic shutdown may also beinstigated by the module 710 or coordinator 118 upon a low power leveldetection of battery system 126 (and such detection may also beaccompanied by a warning or notification signal being transmitted by theprocessor 110 to the base station 160).

[0104] At 890, the downloaded data is processed to create stop sign ortraffic signal violation citations, traffic tickets, or warnings thatcan be transmitted to the operator or owner of the vehicle 134. Theprocessing may include magnifying or enlarging the display of thelicense plate or operator of the vehicle 134 and include otherprocessing discussed with reference to FIGS. 1-6. Generally, thecreation of the citation at 890 includes identifying license platenumbers in the captured images, matching registered owner information tothe numbers (e.g., in a state's motor vehicle database), and printing aticket including the owner's name and mailing address along with theviolation (e.g., running a stop sign, failing to stop at a trafficlight, and the like) and parameter (e.g., time and date and location)information.

[0105] In one embodiment of the system 700, the system 700 is utilizedfor monitoring violators of a traffic signal when the signal has turnedred. In other words, the stop “sign” is a traffic signal or light. Inthis embodiment, the system 700 includes a wired or wireless input (notshown) for receiving a signal indicating the state or status of thetraffic signal. The signal may be generated by a separate device usefulfor determining light status, such as a device with a camera andprocessor for determining the state of the signal. In one embodiment,the signal is received from the targeted or monitored traffic signaldevice itself, which provides signals to indicate when the traffic lightis red and a signal from the traffic signal device when the trafficlight is green again. The module 710 (or other components of processor110) operates to only monitor signals from the laser speed detector 130when the light is red as indicated by the signals from the trafficsignal device. When the light is red, operation of the system 700 inthis embodiment is similar to that described relative to FIGS. 7 and 8with laser 130 and camera 140 generally directed to a particular lane724 or particular lanes 724 (if more than one camera 140 and detector130 are utilized in system 700).

[0106] In another embodiment of the system 700, the digital camera 140positioned in front or back of the sign 720 is supplemented or replacedby a video camera to allow a short video, such as a 5 to 10 second clip,to be captured of the stop sign violation. In this embodiment, the videocamera is triggered by the processor 110 as soon as a speed is detectedby the detector 130 that is above the threshold as determined by themodule 710 or other software/hardware of processor 110. In order tocapture enough video footage, the system 700 may have to be adjusted toutilize a detector 130 with a larger measurement window or that has beenset to detect a speed farther away from the stop sign (such as 20 to 50feet in front of the stop sign 720 in the lane 724). In the earlierdetection embodiment, the capture speed threshold would be set higher asthe vehicle 134 would have a larger distance to stop. Alternatively, asecond detector 130 may be provided that functions simply in detecting apossible violation by a vehicle 134 at a preset distance behind a stopsign 720. This second detector 130 would detect a speed above athreshold (the same or more likely higher than the capture speedthreshold) and the module 710 would first trigger the video based onthis comparison. Then, the second detector 130 would detect a secondspeed within the enforcement or measurement window discussed previouslyand if determined above the capture speed threshold, the module 710would save the video footage or mark the video for later use in provingthe violation and after a set time period, terminate operation of thevideo camera (or the camera may be programmed to only capture a setlength of footage each time it is instructed to operate by the processor110).

[0107] Although the invention has been described and illustrated with acertain degree of particularity, it is understood that the presentdisclosure has been made only by way of example, and that numerouschanges in the combination and arrangement of parts can be resorted toby those skilled in the art without departing from the spirit and scopeof the invention, as hereinafter claimed. For example, the system 100can readily be used in daylight and at night with the addition ofinfrared and other flash devices or flood lighting.

[0108] Further, in one preferred embodiment, the portable fieldprocessor 110 is configured such the memory 120 or a separate memory(not shown) is readily removable. For example, it may be desirable thatfield officers or operators have their own processor 110 and simplyexchange data at the end of shifts or the operators may simply havetheir own removable media and share the same processor 110. This can beachieved with removable storage media, such as compact disks, floppydisks, flash cards, portable USB storage devices, and the like. Thememory 120 or other memory to support this removable media may be aseparate data storage device linked (such as with USB port) to theprocessor 110. This configuration allows ready removal of data storagemedia and also facilitates field restoration of the application (systemcoordinator 118) if lost during field use (i.e., the application may bedownloaded in the field by an operator).

We claim:
 1. A system for field or onsite use in determining a failureof a vehicle to stop at a traffic sign or signal and capturing images ofthe vehicle, comprising: a laser-based speed detector determining aspeed of a vehicle in an enforcement window adjacent the sign or signaland in response, generating a speed signal; a camera aligned with thespeed detector capturing and storing an image of the vehicle, whereinthe camera is adapted for operating in response to an image capturesignal; and a portable field processor communicatively linked with thespeed detector and the camera, wherein the portable field processorreceives the speed signal from the speed detector, compares the speedsignal to a capture speed threshold, and when the threshold isdetermined to be exceeded, transmits the image capture signal to thecamera.
 2. The system of claim 1, wherein the image is a digital-formatstill image of the vehicle stored by the camera in camera memory,wherein the camera responds to the image capture signal to generate andtransmit a digital image file including the digital-format still imageto the portable field processor, and wherein the portable fieldprocessor operates to create a combined speed and image data file bymodifying the digital image file to include speed data from the speedsignal.
 3. The system of claim 2, wherein the digital image file is aJPEG-format file and the modifying includes inserting the speed data ina header of the JPEG-format file.
 4. The system of claim 1, wherein theprocessor includes an input device receiving the capture speed thresholdas inputted by an operator.
 5. The system of claim 4, wherein thecapture speed threshold is less than about 30 miles per hour.
 6. Thesystem of claim 5, wherein the capture speed threshold is selected fromthe range of about 10 to about 20 miles per hour.
 7. The system of claim1, wherein the camera continuously captures and stores images includingone image per image timing cycle, and wherein the portable fieldprocessor synchronizes operation of the detector and the camera bytransmitting the image capture signal within the image timing cycle inwhich the one image is the capture image of the vehicle.
 8. The systemof claim 1, wherein the enforcement window has a front end positioned ina road lane adjacent the sign and about 10 to 20 feet from the sign asmeasured in the lane away from the sign in a direction opposite trafficflow in the lane.
 9. A method of determining violation by a vehicle of atraffic sign or signal that requires the vehicle to stop and capturing adigital image of the vehicle, comprising: positioning a speed detectorand a camera at a location selected relative to the traffic sign orsignal for monitoring vehicle traffic through an enforcement window in aroad lane adjacent the traffic sign or signal; operating the camera onan ongoing basis to capture still images of vehicles passing through theenforcement window and to store the still images at least temporarily inmemory; determining the speed of a targeted vehicle in the enforcementwindow with the speed detector; transmitting the speed from the speeddetector to a portable field processor; processing the speed with theportable field processor to determine whether a capture speed thresholdhas been exceeded and when determined exceeded, transmitting a triggersignal to the camera; and at the camera, receiving the trigger signal,retrieving a still image corresponding to the targeted vehicle frommemory, and transmitting the still image in a digital image file to theportable field processor.
 10. The method of claim 9, further includingprocessing the digital image file with the portable field processor toinsert or link the speed.
 11. The method of claim 10, further includingdisplaying the processed digital image file on a display of the portablefield processor.
 12. The method of claim 9, further including operatingthe camera to provide charging power to the portable field processor toprotect the speed and the digital image file at the portable fieldprocessor.
 13. The method of claim 9, further including prior to theoperating and determining, entering traffic sign or signal enforcementparameters including the capture speed threshold.
 14. The method ofclaim 13, further including operating the portable field processor tocreate a combined digital image file by writing select portions of thetraffic sign or signal enforcement parameters including the speed intothe digital image file.
 15. The method of claim 9, wherein thepositioning includes performing ranging of the speed detector includingfirst aiming the speed detector at the traffic signal, operating thespeed detector to determine a measurement distance from the speeddetector to the traffic sign or signal, and second aiming the speeddetector at a central portion of the road lane.
 16. The method of claim9, wherein the capture speed threshold is selected from the range of 10to 20 miles per hour.
 17. The method of claim 9, wherein the capturespeed threshold is calculated as a percentage of a posted speed limitfor the road lane.
 18. A system for use in determining a failure of avehicle to stop at a traffic sign or signal and for capturing images ofthe vehicle, comprising: means for determining a speed of a vehicle inan enforcement window adjacent the sign or signal and in response,generating a speed signal, wherein the speed determining means comprisesa laser-based speed detector; means aligned with the speed determiningmeans for capturing and storing a video image of the vehicle for ameasurement window, wherein the video image means is adapted foroperating in response to an image capture signal; and processing meanscommunicatively linked with the speed determining means and the videoimage means for receiving the speed signal, comparing the speed signalto a capture speed threshold, determining when the threshold isexceeded, and transmitting the image capture signal to the video imagemeans.
 19. The system of claim 18, wherein the processing means furthergenerates speed data based on the speed signal and wherein theprocessing means further matches the speed data with the video image.20. The system of claim 18, wherein the video image comprises a 10second or shorter video clip of the enforcement window including animage of the vehicle and wherein the video image means responds to theimage capture signal to generate and transmit a video image filecomprising the video clip to the processing means.